Malabsorption of Vitamin D

by Sylvie Tremblay, MSc

About Sylvie Tremblay, MSc

Sylvie Tremblay holds a Master of Science in molecular and cellular biology and has years of experience as a cancer researcher and neuroscientist. Based in Ontario, Canada, Tremblay is an experienced journalist and blogger specializing in nutrition, fitness, lifestyle, health and biotechnology, as well as real estate, agriculture and clean tech.


Vitamin D –- a type of steroid hormone also called calcitriol – is important to your overall health. Your body requires vitamin D to maintain the function of several tissues, including your bones and parathyroid gland. While your body can produce some vitamin D through exposure to ultraviolet light, you can also rely on the intestinal absorption of vitamin D from your diet or via supplements. The inability to properly absorb vitamin D can have adverse effects on your health.

Possible Causes

Malabsorption of vitamin D generally stems from diminished intestinal function, either due to an underlying disorder or as a result of surgery. Because vitamin D is a fat-soluble vitamin, the vitamin is typically found dissolved in fat within your gut. As a result, individuals with an inability to properly absorb fat can also prove unable to absorb vitamin D, according to the Office of Dietary Supplements. In addition, individuals who have had surgery to remove part of their small intestine – such as those who have undergone a gastric bypass – often develop an inability to properly absorb vitamin D from food.

Medication and Vitamin D Absorption

In some cases, medication can interfere with your intestines’ ability to absorb vitamin D efficiently, increasing your risk of vitamin D supplements. Some cholesterol-lowering medications might sequester vitamin D, preventing the proper absorption of the nutrient. In addition, mineral oil –- a treatment for constipation – can bind vitamin D and flush it from your body, preventing proper vitamin absorption. If you take medication that can prevent vitamin D absorption, talk to your doctor about how to avoid a vitamin deficiency.

Possible Effects

Chronic vitamin D malabsorption can potentially lead to vitamin D deficiency if your body cannot synthesize sufficient amounts of the vitamin within your skin. This deficiency can decrease parathyroid hormone production and cause calcium to leach from your bones, causing a decrease in bone density and bone softening. In addition, adults suffering vitamin D deficiency might suffer from muscle pain or weakness. The effects of vitamin D deficiency can prove especially harmful in children, leading to bowed, soft arm and leg bones, as well as soft spots on the skull.


The treatment for vitamin D malabsorption depends on the condition’s underlying cause. Switching medications or modifying a drug dosage might improve vitamin D absorption and protect against vitamin D deficiency. Alternatively, doctors might treat the effects of vitamin D malabsorption through vitamin supplementation. For example, individuals suffering a vitamin D deficiency due to long-term malabsorption might receive regular vitamin D injections to replenish the level of the vitamin within their body to compensate for malabsorption.

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This article reflects the views of the writer and does not necessarily reflect the views of Jillian Michaels or